i disagree about the situation being uncommon (well it is at least plausible) for hiking in the wintertime

i have personally seen it happen and have it somewhat happen to me snowshoeing up a hill on the wintertime

the amount of exertion going up a steel hill on shoes in a pack causes quite a bit of sweat ... i have personally put away down and synth jackets that i have sweated in that turned into a dead bird (or other yuppie) ice scupture

at least with a fleece its cheap, and i can seperate it without damaging it too much

these days i think i know better (i hope) and wear considerably less on the move ... even so in cold enough temps any sweat on yr belay jacket and the snow that gets into it somehow has a nasty tendency of freezing up

We spent six years in a Northern native community in Canada. The lowest temp we saw was -59*C. -20 to -40*C was normal. The idea expressed by the native folk there was that in winter, if you sweat, you die. My experience with down, fleece and synthetic puffy up there is that they're basically right. Takes awhile for a southern lad to get used to working at the necessary level to not sweat, but not freeze either, but working hard enough to sweat can put you in a very bad position faster than you'd think.

Re: “The idea expressed by the native folk there was that in winter, if you sweat, you die.” And, “That's the same that I was taught and practiced for winter hiking - if you sweat, you die, ergo layer to your activity level so that you don't sweat.” This may be where climbers are in a different world than hikers and Native Americans. If you are climbing a route where “if you don’t keep sinking your ice tools into the ice so that you quickly reach a resting place, your muscles will lose all strength, you will slip, and you will die,” you have no choice but to sweat. And you can’t wear less clothing because when you have to do a belay while hanging from an ice screw, you have to have enough clothing that you don’t die of hypothermia. Serious ice climbers are on the razor blade edge between falling and freezing, and you have to have gear that deals with extremes that hikers rarely if ever experience. However, I am no expert.

Robert, In my experience, there is a much higher likelihood of sweating on the approach than on the climb itself. Also, it seems as if you are describing the very reasons why climbers use belay jackets... to insulate during belays. Given this, for me the notion of starting cool and preventing sweat still holds. A thin fleece and schoeller jacket is my NE winter combination for hiking or climbing. In this, when you do sweat, it dries quickly- especially under a synthetic belay jacket.

Michael: Since I'm not an expert, all I can do is report a real-world event with real-world people: “I went to fleece exclusively after topping out on Shoestring in -10º F (before wind-chill) temps, with 30-40 mph gusts. We were working hard and SWEATING HEAVILY WHILE MOVING, and my Capilene 3 and R2 fleece let the sweat out. My partner was wearing a MicroPuff inside his shell, and it was a frozen mess, stuck to his shell and not warm at all any more. It breathes, but not nearly as well as the fleece.” Just out of curiosity, have you ever climbed over-hanging ice? And while doing so, you didn't sweat? And you were able to add and remove a belay parka while moving up that over-hanging ice?

The only Shoestring I am familiar with is the Shoetring Gully on Mt. Webster, NH. If that is what is being referred to, I (personally) would likely sweat more on that climb than on a vertical grade 5 (the steepest I have climbed, and badly at that- I only lead 4s.) simply because one tends to keep moving in a constant fashion, often without stopping to place gear or establish belays. During such climbs, my respiration would increase much more than on a vertical route, and so I would sweat more. My arms would be much more pumped on the vertical ice, however…

With that said, anyone wearing a Micropuff under a shell while climbing, even in those temps, is (IMO) going to sweat. Too much clothing and not enough breathability. Thus, I tend towards 100 weight fleece and uber-breathable Schoeller dryskin softshells (no membranes). I have had an R2 vest stashed in my pack for years and have yet to pull it out for use while moving. I do not even carry WB shells in winter anymore.

One keeps the belay jacket in a pack or on the harness while climbing, and at the belays (a ledge or decent stance with an anchor) they don the jacket to retain heat because they have stopped moving. When you begin moving again, you take the jacket off… if you do not establish a belay, such as on an easy climb such as Shoestring or if you are just a hardcore soloist, you may never need the belay jacket that day. For me, there are moments of simply dealing with being chilled- such as when you initially start moving. One has to fight the urge to be warm all of the time and err on the side of keeping mildly cool in order to combat sweating. At least, this is what has worked for me in the Northeast winters. I have no idea how this will translate to CA, my new home.

Michael, I don’t think you or Eric Chan or my humble self disagree about what the main point is: someone might end up regretting moving to down, or for that matter, staying with a synthetic puffy for actual hiking as opposed to using it for a Belay Jacket, when synthetic underwear under a light shell, in-between stuff like the R1 Hoody under a light shell, or light fleece under a light shell, are best for activity. I tried to limit this rule to climbing because I know people on this site do actual hiking and other activities while wearing a light down garment, but Eric seems to be warning even hikers not to do that. My two-climbers real-world example was to show how any puffy, synthetic or down, is dangerous in active exercise. You also do not use any type of puffy, down or synthetic, except for a Belay Jacket. That was the lesson the one climber learned the hard way, and the other climber learned that his non-puffy stuff worked well, and switched totally and permanently.

Richard... I am confused. Assuming your info I've gathered from across several threads I have the following.

3.7oz x 1.68 = 6.216 x 48% = 2.98 clo 800 fill down jacket.

2.98 clo down jacket + 1 clo base layer = 3.98 clo.

Using your backpacking performance model line graph, a 3.98 clo doesn't cross the camp chores line (2.5MET)at all. Now if the camp chores is meant as the value between the camp chore line and the sitting and talking line, it crosses at 19F.

I'm just confused because I am trying to figure out my own info but the above seems not to jive with this statement:

"The average male, wearing a 1 clo base ensemble, and doing camp chores at the freezing point needs ~3.7 oz. of 800 fill power down to be thermo-neutral."

I know I must be doing something wrong, please help because I planned on using a 3oz Patagonia down sweater and .6 clo base layer to keep me warm sitting and talking down to 35F

there are many ways to skin a cat. kelly cordes (to drop a name) doesn't seem to mind climbing in his puffy if he needs to (http://kellycordes.wordpress.com/2010/01/28/the-micro-belay-parka/ ), but it all needs to be taken in context of the situation, the skill set and physical conditioning of the individual person. just because there's two lines from a story about a frozen puffy is no reason to rule them out completely.

not a down one generally ... also well conditioned athletes sweat less in general for a similar climb than lazy bums like us would

i do know some people who do hike/walk with poofays ... but most of them tend to be female, on flat ground with light loads ... in cold conditions ...

but more often than not if yr hiking with a pack in winter with shoes, up hill ... ive seen more of those people soaking their down puffies with sweat ... and if thats yr only insulation layer, you are in a very dangerous situation in winter ...

i personally dont see any reason to use a 800-900 fill down garment as an active midlayer if theres any chance of sweating in it ... that 900 fill down will likely be more like 700 or less fill even at 50% humidity levels

the key to synth isnt that they are good when wet ... fleece is much better for that ... but that you can make a decent effort of drying it out with body heat ... something you probably cant with down ... and that they do combine a windshirt and "fleece" in one for a lighter weight than fleece

of course a fleece is much more durable and breathable ... imagine wearing 2 windshirts and a fleece sandwiched between them ,... thats basically what a synth poofay is ...

everybody finds what works for them of course ... but in general ... if yr always sweating for more than occasional burst, yr likely doing it wrong ...

its quite surprising how many people overheat in winter ... then they shiver because they are soaked in sweat

Re: " just because there's two lines from a story about a frozen puffy is no reason to rule them out completely."Someone attended a slide show, and posted this report:“Here's a summary from Colin Haley’s talk: CLOTHING:- BASE LAYERS, LEGS AND UPPER BODY - For comfort, use wool instead of Capilene because wool dries out slower, hence it has a slower evaporative heat loss, and your body doesn’t get hit as hard with a flash freeze effect.- MID LAYERS, LEGS - When very cold, use a base layer, fleece pants, then softshell pants. - He prefers non-zip softshell vs hard shells. Soft breathes better. - Patagonia synthetic puff pants with full-off zips are useful for very cold. - MID LAYERS, UPPER BODY - Base layer, fleece, then windshirt. Add a hard shell if it gets colder. - He prefers a hardshell for the top since its easy to take off and on, while he prefers non-zip softshell for pants, which can’t be easily taken off or on.- OUTER, INSULATION LAYER, UPPER BODY - He prefers synthetic to down because on a climb, clothing is constantly coming in contact with snow. He uses a Patagonia Nano puff as his warm layer for summer snow climbs, and he adds on the DAS parka when it get colder. - SOCKS - Vapor barrier socks can be useful to add warmth. Something which is not totally VB can work too, like the REI hyperlight storm sock. A clean dry pair of socks for sleeping is good.SHADES- instead of carrying goggles and shades, uses the new (not yet in USA) Addidas Terrex shades : modular so it can go from shades to goggle with nose protection

The clo values for the jacket and base layers are the intrinsic clo values. They are additive but don’t include the boundary layer calculation if you are sheltered from the wind. If you are an average 30 year old male, sheltered from the wind (+ .6 clo boundary layer), and doing camp chores (1.75 MET average), then a 3 oz. Patagonia Down Sweater combined with a 1 clo base layer ensemble will yield a thermo-neutral temperature of 35F… as you correctly planned. If you use a 3.7 oz fill down jacket in the above scenario, the thermo-neutral temp is 32F (freezing).